Log feeding device

ABSTRACT

A centering and guiding log feeding device including oppositely disposed, readily compressible, resilient rollers between which logs are passed as they are fed into a sawing apparatus. In the overall sawing system, one device is positioned ahead of a scragg saw which cuts a log into a cant having two opposite, flat sides. Another centering and guide device is positioned ahead of a gang edger and downstream from the scragg saw and centers, and guides the cant received from the scragg saw into the gang edger where the cant is cut into usable boards.

United States Patent [191 Sweet et al.

[ 51 Feb. 18, 1975 I LOG FEEDING DEVICE [75] Inventors: Harold J. Sweet,Rhinelander; John G. Grimm, Jr., Tripoli, both of Wis.

[73] Assignee: Marplex Products Co., Inc.,

Rhinelander, Wis.

[22] Filed: Dec. 26, 1972 [21] Appl. No.: 318,104

[52] US. Cl. 144/3 R, 144/3 P, 144/41, 144/246 A, 144/246 E, 144/312,198/167 [51] Int. Cl. B27c 9/04 [58] Field of Search 83/4253, 425.4;144/3 R, 144/3 P, 41, l R, 134 R, 242 R, 242 C, 246

R, 246 A, 246 B, 246 C, 312, 246 E, 246 F,

208 R, 208 F, 208 E; 198/167 56] References Cited UNITED STATES PATENTS561,569 6/1896 Davidson 144/246 G 1,437,843 12/1922 Heinrichs 144/246 AUX 1,798,570 3/1931 Wahl 144/246 B 2,765,011 10/1956 Jackson 144/208 F2,794,466 6/1957 Leffler 144/246 F 2,923,333 2/1960 Nicholson i98/167 X3,344,826 10/1967 Mitten 144/3 R FOREIGN PATENTS OR APPLICATIONS1,086,035 7/1960 Germany 144/246 R Primary Examiner-Andrew R. JuhaszAssistant ExaminerW. D. Bray [57] ABSTRACT A centering and guiding logfeeding device including oppositely disposed, readily compressible,resilient rollers between which logs are passed as they are fed into asawing apparatus. In the overall sawing system, one device is positionedahead of a scragg saw which cuts a log into a cant having two opposite,flat sides. Another centering and guide device is positioned ahead of agang edger and downstream from the scragg saw and centers, and guidesthe cant received from the scragg saw into the gang edger where the cantis cut into usable boards.

20 Claims, 8 Drawing Figures PATENTEB FEB I BIS- 5 SHEEI 10F 4 n l I 2%is .5... 5.5.:

LOG FEEDING DEVICE BACKGROUND OF THE INVENTION The present inventionrelates to a device for centering and guiding logs or the like as theyare fed into a sawing apparatus or the like. To our knowledge, no suchdevice is presently available which is capable of feeding logs into asawing apparatus at speeds of more than 50 feet per minute. Even then,present devices are incapable of handling logs having excessiveirregularities in their surfaces.

Prior art devices generally include oppositely disposed, inwardlyslanted steel roller wheels which tend to cradle a leg as the logs arefed into sawing apparatus. In some devices, the surfaces of theserollers are spiked or starred in order to more positively engage thesurface of a log. One device includes a number of sets of spiked, steelrollers, the rollers of each set arrayed in a triangular fashion arounda log and biased inwardly towards one another. These rollers changeposition with respect to one another as a log is passed therethrough.

None of these devices will operate satisfactorily at high rates ofspeed. None of these devices work at all in centering logs which areparticularly irregular in shape. Thus, it is particularly difficult tofind suitable apparatus for producing lumber for use in low cost lumberapplications. The frequency of occurrence of logs having large knots,swaybacks and other irregularities in their surface is particularly highin timber which is sufficiently economical for use in producing low costlumber.

SUMMARY OF THE INVENTION The present invention comprises a method andapparatus in which the opposite sides of a log are engaged by a pair ofoppositely disposed, readily compressible, resilient members as the logis moved into a sawing apparatus or the like. These readilycompressible, resilient members tend to absorb irregularities in thesurface or configuration of the log while still holding the loggenerally on the center line of the path along which it moves as itmoves into the sawing apparatus. Preferably, the readily compressible,resilient members comprise at least one pair of oppositely disposed,readily compressible resilient rollers spaced such that the distancebetween them is less than the approximate diameters of logs passingtherebetween.

Logs can be passed through centering and guiding devices embodying thepresent invention at speeds as high as ISO to 200 feet per minute. Theireffectiveness is illustrated graphically by the cut which was madethrough the cant shown in FIG. 8. FIG. 8 shows a plan view of an actualcant after it had been guided through a gang edger by a centering andguiding device embodying the present invention.

Preferably, the readily compressible, resilient rollers are rotatablymounted on the ends of pivot arms which in turn are pivotally mounted ona frame. Bias means are operably connected between each pivot arm andthe frame for biasing the rollers towards one another. This enables thedevice to compensate for overall changes in log diameter, while thecompressible rollers themselves accommodate localized irregularities inthe log surface. Preferably, the bias means is adjustable so that lessresistance can be set for runs of a number of logs having generallylarger diameters while greater resistance can be set for runs of logshaving generally narrower diameters. This makes it unnecessary to adjustthe positions of the rollers themselves.

One overall system employs one centering device ahead of a scragg sawand another centering device downstream from the scragg saw but ahead ofa gang edger. The scragg saw is used to cut the log into a cant havingtwo opposite flat surfaces. The gang edger is used to cut the cant intofinished boards. Preferably, a feed table is positioned ahead of thegang edger which includes driven rollers oriented at an angle to a flatguide member such that the cant is driven into engagement with the guidemember and is rolled over on one of its flat surfaces prior to being fedinto the second centering and guiding device.

This invention is particularly invaluable in producing lumber from lowgrade logs. One illustrative application is in the production of lumberfor use in making wooden shipping pallets. Other applications for theinvention, as well as additional objects, advantages and features willbe apparent by reference to the written specification and appendeddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a generally schematicview of an overall sawing system employing two centering and guidingdevices and two sets of saws;

FIG. 2 is a top plan view of the first centering and guiding device;

FIG. 3 is a side elevational view of the first centering and guidingdevice;

FIG. 4 is a fragmentary perspective view showing one readilycompressible, resilient roller and its pivot mounting arm;

FIG. 5 is a top plan view of the second centering and guiding device andof its attendant feed table;

FIG. 6 is a side elevational view of the second centering and guidedevice and feed table;

FIG. 7 is a fragmentary perspective view of a readily compressible,resilient roller and its attendant pivot mounting arm; and

FIG. 8 is an elevational view of an actual cant after it had been fedinto a gang edger by a centering and guide device embodying the presentinvention.

PREFERRED EMBODIMENT The overall sawing system 1 disclosed in the preferred embodiment employs two very similar centering and guiding devices10 and 20 embodying the present invention. One is positioned ahead of ascragg saw 2 and the other ahead of a gang edger 4 and downstream fromthe scragg saw 2 (FIG. I). A log is first conveyed through centeringdevice 10 and! into scragg saw 2. Scragg saw 2 cuts the log into a canthaving two opposite flat sides. The cut side boards fall out of thesystem down opposite sides of side board chute 3. The cant is thendelivered to feed table 30 which rolls the cant over onto one of itsflat surfaces and feeds it into the second centering device 20. Thesecond centering device 20 feeds, guides and centers the cant into agang edger 4 which cuts the cant into the finished boards.

Each of the centering devices 10 and 20 is similarly constructed in thateach includes a plurality of oppositely disposed, readily compressible,resilient rollers 50 between which logs are passed (compare FIGS. 2 and5). The rollers 50in turn are rotatably mounted on the ends of pivotarms 60 which in turn are pivotally mounted on a frame 80a for firstdevice 10 or a frame 80b for second device 20. In the case of bothcentering devices, the pivot arms 60 are biased to pivotal movementtowards one another by an air spring 70 operably connecting the end ofeach pivot arm 60 to an anchor arm 86 of frame 80a or frame 80b (compareFIGS. 4 and 7). In operation, the readily compressible, resilient rollermembers 50 absorb localized irregularities in the configuration of a logpassing therethrough while air springs 70 allow rollers 50 to flexfarther away from one another or closer towards one another in order toaccommodate runs of a number of logs having generally larger orgenerally smaller diameters, respectively.

The rollers 50 employed in both the first centering and guide device 10and second centering and guide device 20 are identical. They are readilycompressible so that they absorb irregularities in the surface of a logpassing therethrough and they are resilient so that they return to theiroriginal configuration after the log has passed. Zero pressure tires ofthe type employed in all terrain vehicles have been found to workexceptionally well as rollers 50 (FIGS. 4 and 7). They are filled to anair pressure which is just sufficient to hold their shape. Thus, theyare filled to a pressure of around 1% pounds.

The differences between the first and second centering devices 10 and 20result from their differing applications in the overall system.Primarily, these differences are in the means whereby logs are movedbetween rollers 50 and in the structure of their respective frames 80aand 80b. These in turn require the minor differences in theconfigurations of pivot arms 60.

First centering and guide device 10 is designed for feeding rough logsinto the scragg saw 2. Since it doesnt matter where the log is engagedor how its surface is affected, a dog chain 100 can be used to drive thelog between the oppositely disposed rollers 50 of first centering device10 (FIG. 2). All of the rollers 50 of first centering device 10 arefreely rotatably mounted and are rotated merely as a result ofengagement by a passing log.

Second centering and guide device 20, on the other hand, is specificallyadapted for feeding the two-sided cant which is delivered from scraggsaw 2 into the finishing gang edger 4. It is not possible to drive thecant through the centering device 20 with a dog chain such as dog chain100 since the smooth, fiat surface upon which the cant will lay cannotreadily be gripped by the dogs ofa dog chain. Accordingly, secondcentering and guide device 20 includes a plurality of driven rollers 110mounted on its frame 80b (FIGS. 5 and 6). Additionally, the first tworotatably mounted rollers 50 of second centering device 20 are driven bya hydraulic motor 120 mounted on frame 80b each pivot arm 60 (FIG. 6).Suitable hydraulic connections are provided. These provide the primarymeans for driving a log through the remaining three pairs of rollers 50,the remaining 3 pairs of rollers 50 being freely rotatable. The drivenrollers 110 assist in driving a log therethrough.

The pivot arms 60 upon which readily compressible, resilient rollers 50are mounted are basically the same for both centering and guide device10 and (compare F168. 4 and 7). Each pivot arm 60 includes a main arm 61which extends to both sides of a pivot shaft 64 which passestherethrough. A vertical arm 62 extends upwardly from main arm 61approximately at its pivot point. A top arm 63 extends from the top ofvertical arm 62 outwardly to a position over the end of main arm 61 sothat a readily compressible, resilient roller 50 can be rotatablymounted between the ends of top arm 63 and main arm 61. Each roller 50is rotatably mounted on a shaft 51 which extends between the ends ofarms 61 and 63. Pivot shaft 64 is then mounted in appropriate barrackson either frame 800 or frame 80b for first or second centering andguiding devices 10 or 20, respectively.

The only essential difference between the pivot arms 60 shown in FIGS. 4and 7 is that the pivot arm 60 shown in FIG. 7, for use in the secondcentering and guide device 20, includes an extension 68 dependingdownwardly from that end of main arm 61 which is away from roller 50.The purpose of extension 68 is to provide a more convenient mountingpoint for mounting air spring 70 between pivot arm 60 and frame b. Sincerollers 110 take up more space below the level of rollers 50 than doesdog chain 100, extension 68 is required to effectively place the end ofpivot arm 60 in juxtaposition to a suitable portion of frame 80b betweenwhich air springs 70 can be connected. For pivot arm 60 for use in firstcentering and guide device 10 (FIG. 4), air spring 70 is convenientlymounted directly to the end of main arm 61.

Frame 80a of first centering device 10 includes a pair of spaced, toplongitudinal beams 81 joined together by three spaced top lateral beams82 (FIGS. 2 and 3). This top assembly is joined to a pair of spacedbottom longitudinal beams 83 by means of a pair of spaced vertical beams88 on either side of frame 80a. The bottom longitudinal beams 83 in turnare joined by three bottom lateral beams 84.

To facilitate mounting of anchor arms 86 to frame 80a, a pair ofsupplemental longitudinal beams 85 extend longitudinally of frame 80a ontop of bottom lateral beams 84. Four of the six anchor arms 86 which actas an anchor to which air springs 70 are mounted, are mounted on top ofsupplemental longitudinal beams 85 and on top of bottom longitudinalbeams 83 (FIG. 2). Specifically, the anchor arms 86 for the last twopairs of rollers 50 are mounted in this manner. They are cocked at anangle with respect to frame 80a and with respect to longitudinal beams83 and 85 which is approximately the same as the angle at which pivotarms 60 are cocked. Since the lead pair of anchor arms 86 must extendbeyond the end of frame 80a, they are welded directly to the firstlateral crossbeam 84 (see FIG. 3). An anchor plate 87 extends upwardlytherefrom to a point in alignment with the end of main arm 61 of pivotarm 60 such that an air spring 70 can be mounted between anchor plate 87and the end of main arm 61.

In first centering device 10, the pivot shaft 64 for pivot arms 60 aremounted in bearings which are secured to lateral beams 82 at the top andbottom lateral beams 84 at the bottom.

Frame 80b for second centering device 20 comprises four square boxframes 91 (FIGS. 1, 5 and 6). A pair of top longitudinal beams 92 aremounted on top of box frames 91 and extend generally the length ofcentering device 20 and beyond the front end thereof to a point abovefeed table 30. The bottom crossbeams of box frames 91 pass beneath a bedframe 93 which provides the basic support for box frames 91. Bed frames93 comprises a generally rectangular frame having legs extendingdownwardly therefrom.

The driven steel rollers 110 are mounted on top of bed frame 93. Pivotshaft 64 of pivot arms 60 are rotatably mounted in bearings which ineach case are secured to the top cross frame member of box frame 91(FIG. 7). The anchor arms 86 to which air springs 70 are mounted arewelded to the bottom crossbeam of box frame 91 and lie generallyparallel to pivot arms 60. Extension 68 extends downwardly generallyinto juxtaposition with the end of anchor arm 86 and air spring 70 ismounted between the end of anchor arm 86 and the bottom end of extension68 (FIG. 7).

Each of the air springs 70 comprises a hollow rubber member mountedbetween two end plates, such air springs being available commercially.Each air spring 70 includes a valve stem 71 extending therefrom whichfacilitates filling air springs 70 to varying pressures (FIGS. 4 and 7).Typically, air springs 70 as used in the present invention are filled toapproximately 5 pounds. However if a run of smaller diameter logs are tobe passed through centering devices 10 and 20, air springs 70 can befilled to a greater pressure such that rollers 50 are biased morestrongly towards one another. For runs of larger diameter logs, air canbe let out of air springs 70 so that rollers 50 can be spread apart morereadily to accommodate larger diameter logs.

Feed table 30 which is associated with second centering device receivesa cant after the side boards have fallen off a chute 3 and rotates thecant over onto its side and centers the log generally with respect tocentering device 20. To accomplish this result, a plurality of steelrollers 31 are mounted on a frame 32 cocked at a slight angle to a guide35 which is also mounted on frame 32 and extends generally the lengththereof (FIG. 5). Guide 35 comprises a long, straight steel beampositioned at one side of frame 32. All of the rollers 31 are driven,the end roller being driven by a motor 33 and successive rollers beingdriven by inter mediate drive chains 34. Because the steel rollers 31are inclined at an angle to guide 35, they tend to drive a cant towardsguide 35. When the log hits guide 35, or possibly even before. therotating steel rollers 31 tend to roll the cant over onto its flat side.This insures that the cant will be properly oriented as it is fed intocentering device 20 and as centering device 20 feeds the cant into gangedger 4.

In order to positively drive the cant into engagement with the first twodriven rollers 50 of centering device 20, a spur feeder 40 is mounted totop longitudinal beams 92 above feed table (FIG. 6). Spur feeder 40comprises a toothed spur wheel 41 rotatably mounted on the end of asupport arm 42. Support arm 42 is in turn pivotally mounted at itsopposite end on a drive shaft 47. Drive shaft 47 is rotatably mountedbetween a pair of spaced, downwardly depending mounting plates 48 whichare welded to top longitudinal beams 92. A motor 44 mounted on top oftop longitudinal beams 92 drive shaft 47 which in turn drives spur wheel41 by means of interconnecting drive chain 43. A support chain 45extends downwardly from a cross-beam 92a which extends between toplongitudinal beams 92 (FIG. 5). Support chain 45 holds spur feeder 40suspended. Mounted between a second crossbeam 92b and support arm 42 isan air spring 46 which biases spur wheel 41 downwardly firmly againstthe surface of a cant being fed into rollers 50.

Motor 33 which drives steel rollers 31 also drives the steel rollers 110which are positioned below compressible rollers 50 in second centeringdevice 20. A drive chain 34 extends from the last steel roller 31 to auniversal drive member 111 which in turn is connected to the first steelroller 110 (FIG. 5). A plurality of interconnecting drive chains 112then drive successive rollers 110.

In operation, a log is conveyed by dog chain to the first centeringdevice 10. Dog chain 100 drives the log entirely through centeringdevice 10 and into scragg saw 2 (FIGS. 1 and 2). As the log passesbetween the freely rotatable rollers 50, it is positively centeredthereby. Local irregularities in the surface or configuration of the logare absorbed by the readily compressible, resilient rollers 50. Toaccommodate variations in overall diameter, air springs 70 compressinwardly and push outwardly. Once the log reaches scragg saw 2, thedrive means of the scragg saw 2 itself take over and finally drive thelog through the saw.

At chute 3, the side boards which have been cut off of either side ofthe log fall off. The resulting cant includes two flat sides which atthis point, areoriented generally vertically. The cant is conveyed by adog chain onto roller feed table 30. If the cant has already not fallenover on its flat side, the driving action of rollers 31 cause it to doso. Because the driven rollers 31 are oriented at an angle to guide 35,the cant is driven against the side of guide 35 and into position belowspur feeder 40. Spur wheel 41 of spur feeder 40 engages the cant and,with the help of driven rollers 31, drives the cant into positionbetween the first two rollers 50 of second centering device 20 (FIGS. 5and 6). These first two rollers 50 are driven by motors 120. Thus, thefirst pair of rollers 50 serve not only as centering means, but also asa drive means for driving the cant forwardly. These driven rollers 50,along with the driven steel rollers which are positioned below rollers50, drive the cant forwardly through the remaining three pair of idlerrollers 50. As with the rollers 50 of centering device 10, these rollers50 serve to absorb local irregularities in the surface and configurationof the log while the air springs 70 accommodate variations in overalldiameter of the cants. The cants are driven into engagement with thedrive means of gang edger 4 which finally cuts the cant into boardshaving the desired dimensions.

The cant shown in FIG. 8 graphically illustrates the exceptional natureof this contribution to the art. The cant shown in FIG. 8 was deliveredto the gang edger at a speed of in excess of feet per minute. Yet, thecant was centered with respect to gang edger 4 in the most optimumpossible manner. Such an irregularly shaped cant could not possibly havebeen handled by conventional centering and sawing devices.

Of course, it is understood that the above is merely a preferredembodiment of the invention and that various alterations thereof may bemade without departing from the spirit and broader aspects of theinvention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A device for centering moving logs or the like as they are fed into asawing apparatus or the like, said device comprising: a supportingframe; at least one pair of generally oppositely disposed pivot arms,each pivotally mounted on said frame; a readily compressible, re-

silient roller for each said pivot arm, rotatably mounted I on saidpivot arm at a point spaced from the pivot point of said pivot armwhereby said readily compressible, resilient rollers are pivotabletowards and away from one another; bias means operably connecting saidpivot arm and said frame to thereby bias said rollers to pivotablemovement towards one another whereby when a log passes between saidrollers, said rollers compress individually and pivot away from oneanother to absorb irregularities in a log or the like while stillholding said log or the like generally centered therebetween.

2. The device of claim 1 in which said bias means is operably connectedto said pivot arm at a point spaced from its pivot point and on theopposite side of said pivot point from said readily compressible,resilient roller.

3. The device of claim 1 in which said bias means comprises an airspring.

4. The device of claim 3 in which said air spring is filled to apressure of approximately five pounds.

5. The device of claim 3 in which each said air spring includes meansfor varying the air pressure therein to increase or decrease the extentto which said rollers can be pivoted away from one another whereby saiddevice can be adjusted to accommodate differing sized logs.

6. The device of claim 3 in which a number of pairs of said pivot armsand said rollers are spaced along the path followed by a log as it isfed into a sawing apparatus or the like, said pairs of pivot arms androllers extending for a distance approximately equal to the length of alog being passed therethrough whereby the entire length of the log iscontrolled as the log enters a sawing apparatus.

7. The device of claim 3 in which said readily compressible, resilientrollers comprise hollow, air-filled members filled with air to apressure just sufficient to inflate said hollow members and cause themto hold their shape until engaged by a log or the like.

8. The device of claim 7 in which said hollow, airfilled rollers arefilled to a pressure of approximately lVz pounds; each said air springincluding means for varying the air pressure therein to increase ordecrease the extent to which said rollers can be pivoted away from oneanother whereby said device can be adjusted to accommodate differingsized logs.

9. The device of claim 8 in which said air spring is filled to apressure of approximately pounds.

10. The device of claim 1 in which one pair of said readilycompressible, resilient rollers are rotatably driven the rest of saidrollers being freely rotatable; said driven rollers being positionedahead of said freely rotatable rollers for driving a log through saidfreely rotatable rollers and into a sawing apparatus or the like; amotor mounted on each pivot arm carrying a driven roller, said motorbeing operably connected to said driven roller for driving the same.

11. The device of claim 1 in which said bias means includes means forvarying the bias strength thereof whereby said device can be adjusted toaccommodate differing sized logs.

12. A device for sawing logs or the like comprising: a first sawingapparatus for sawing a log into a cant having two opposite flat sides; afirst centering and guiding device for centering logs as they are movedinto said first sawing apparatus, said centering device including atleast two readily compressible, resilient rollers spaced on oppositesides of a path which is centered with respect to said first sawingapparatus, said centering and guiding device comprising the final guidemeans which control said log as it passes into said sawing apparatus; asecond sawing apparatus for sawing said cant into boards; a secondcentering device positioned behind said first sawing apparatus and aheadof said second sawing apparatus for centering and guiding said cants asthey are moved into said second sawing apparatus, said second centeringand guiding device comprising at least two oppositely disposed, readilycompressible, resilient rollers spaced on opposite sides of a path whichis centered with respect to said second sawing apparatus, said secondcentering and guiding device comprising the final guide means whichcontrols the centering of a log as it passes into said second sawingapparatus.

13. The device of claim 12 in which said second centering and guidingdevice includes a plurality of driven feed rollers positioned ahead ofsaid readily compressible, resilient rollers, a straight, generally flatguide positioned above said feed rollers; said feed rollers beingdisposed at an angle to said guide so that said feed rollers drive saidcant into said guide and cause it to roll over onto a flat side suchthat the unsawed, rough sides of said cant are engaged by said readilycompressible, resilient rollers of said second centering and guidingdevice as said cant passes therethrough.

14. The device of claim 13 which includes a driven wheel positionedabove said driven feed rollers and immediately ahead of said readilycompressible, resilient rollers whereby said cant is engaged by saidwheel and driven thereby into position between said readilycompressible, resilient rollers.

15. The device of claim,l3 in which each said centering and guidingdevice comprises: a number of pairs of said readily compressible,resilient rollers spaced along the path followed by a log as it is fedinto a sawing apparatus, said pairs of rollers extending for a distanceapproximately equal to the length of a log whereby the entire length ofa log is controlled as it begins to enter a sawing apparatus.

16. The device of claim 15 in which said second centering and guidingdevice includes means for rotating at least one pair of saidcompressible, resilient rollers, the rest of said rollers being freelyrotatable, said driven rollers being positioned ahead of saidfreewheeling rollers whereby said driven rollers drive said cant throughsaid freely rotatable rollers and into said second sawing apparatus.

17. The device of claim 16 in which said first centering and guidingdevice in which all of said readily compressible, resilient rollers arefreely rotatably mounted, said first centering and guiding deviceincluding a drive chain passing generally between said rollers fordriving a log therebetween.

18. The device of claim 12 in which each said centering and guidingdevice comprises: a number of pairs of said readily compressible,resilient rollers spaced along the path followed by a log as it is fedinto a sawing apparatus, said pairs of rollers extending for a distanceapproximately equal to the length of a log whereby the entire length ofa log is controlled as it begins to enter a sawing apparatus.

19. The device of claim 18 in which said second centering and guidingdevice includes means for rotating at least one pair of said readilycompressible, resilient 10 ing and guiding device in which all of saidreadily compressible, resilient rollers are freely rotatably mounted,said first centering and guiding device including a drive chain passinggenerally between said rollers for driving a log therebetween.

1. A device for centering moving logs or the like as they are fed into asawing apparatus or the like, said device comprising: a supportingframe; at least one pair of generally oppositely disposed pivot arms,each pivotally mounted on said frame; a readily compressible, resilientroller for each said pivot arm, rotatably mounted on said pivot arm at apoint spaced from the pivot point of said pivot arm whereby said readilycompressible, resilient rollers are pivotable towards and away from oneanother; bias means operably connecting said pivot arm and said frame tothereby bias said rollers to pivotable movement towards one anotherwhereby when a log passes between said rollers, said rollers compressindividually and pivot away from one another to absorb irregularities ina log or the like while still holding said log or the like generallycentered therebetween.
 2. The device of claim 1 in which said bias meansis operably connected to said pivot arm at a point spaced from its pivotpoint and on the opposite side of said pivot point from said readilycompressible, resilient roller.
 3. The device of claim 1 in which saidbias means comprises an air spring.
 4. The device of claim 3 in whichsaid air spring is filled to a pressure of approximately five pounds. 5.The device of claim 3 in which each said air spring includes means forvarying the air pressure therein to increase or decrease the extent towhich said rollers can be pivoted away from one another whereby saiddevice can be adjusted to accommodate differing sized logs.
 6. Thedevice of claim 3 in which a number of pairs of said pivot arms and saidrollers are spaced along the path followed by a log as it is fed into asawing apparatus or the like, said pairs of pivot arms and rollersextending for a distance approximately equal to the length of a logbeing passed therethrough whereby the entire length of the log iscontrolled as the log enters a sawing apparatus.
 7. The device of claim3 in which said readily compressible, resilient rollers comprise hollow,air-filled members filled with air to a pressure just sufficient toinflate said hollow members and cause them to hold their shape untilengaged by a log or the like.
 8. The device of claim 7 in which saidhOllow, air-filled rollers are filled to a pressure of approximately 11/2 pounds; each said air spring including means for varying the airpressure therein to increase or decrease the extent to which saidrollers can be pivoted away from one another whereby said device can beadjusted to accommodate differing sized logs.
 9. The device of claim 8in which said air spring is filled to a pressure of approximately 5pounds.
 10. The device of claim 1 in which one pair of said readilycompressible, resilient rollers are rotatably driven the rest of saidrollers being freely rotatable; said driven rollers being positionedahead of said freely rotatable rollers for driving a log through saidfreely rotatable rollers and into a sawing apparatus or the like; amotor mounted on each pivot arm carrying a driven roller, said motorbeing operably connected to said driven roller for driving the same. 11.The device of claim 1 in which said bias means includes means forvarying the bias strength thereof whereby said device can be adjusted toaccommodate differing sized logs.
 12. A device for sawing logs or thelike comprising: a first sawing apparatus for sawing a log into a canthaving two opposite flat sides; a first centering and guiding device forcentering logs as they are moved into said first sawing apparatus, saidcentering device including at least two readily compressible, resilientrollers spaced on opposite sides of a path which is centered withrespect to said first sawing apparatus, said centering and guidingdevice comprising the final guide means which control said log as itpasses into said sawing apparatus; a second sawing apparatus for sawingsaid cant into boards; a second centering device positioned behind saidfirst sawing apparatus and ahead of said second sawing apparatus forcentering and guiding said cants as they are moved into said secondsawing apparatus, said second centering and guiding device comprising atleast two oppositely disposed, readily compressible, resilient rollersspaced on opposite sides of a path which is centered with respect tosaid second sawing apparatus, said second centering and guiding devicecomprising the final guide means which controls the centering of a logas it passes into said second sawing apparatus.
 13. The device of claim12 in which said second centering and guiding device includes aplurality of driven feed rollers positioned ahead of said readilycompressible, resilient rollers, a straight, generally flat guidepositioned above said feed rollers; said feed rollers being disposed atan angle to said guide so that said feed rollers drive said cant intosaid guide and cause it to roll over onto a flat side such that theunsawed, rough sides of said cant are engaged by said readilycompressible, resilient rollers of said second centering and guidingdevice as said cant passes therethrough.
 14. The device of claim 13which includes a driven wheel positioned above said driven feed rollersand immediately ahead of said readily compressible, resilient rollerswhereby said cant is engaged by said wheel and driven thereby intoposition between said readily compressible, resilient rollers.
 15. Thedevice of claim 13 in which each said centering and guiding devicecomprises: a number of pairs of said readily compressible, resilientrollers spaced along the path followed by a log as it is fed into asawing apparatus, said pairs of rollers extending for a distanceapproximately equal to the length of a log whereby the entire length ofa log is controlled as it begins to enter a sawing apparatus.
 16. Thedevice of claim 15 in which said second centering and guiding deviceincludes means for rotating at least one pair of said compressible,resilient rollers, the rest of said rollers being freely rotatable, saiddriven rollers being positioned ahead of said freewheeling rollerswhereby said driven rollers drive said cant through said freelyrotatable rollers and into said second sawing apparatus.
 17. The deViceof claim 16 in which said first centering and guiding device in whichall of said readily compressible, resilient rollers are freely rotatablymounted, said first centering and guiding device including a drive chainpassing generally between said rollers for driving a log therebetween.18. The device of claim 12 in which each said centering and guidingdevice comprises: a number of pairs of said readily compressible,resilient rollers spaced along the path followed by a log as it is fedinto a sawing apparatus, said pairs of rollers extending for a distanceapproximately equal to the length of a log whereby the entire length ofa log is controlled as it begins to enter a sawing apparatus.
 19. Thedevice of claim 18 in which said second centering and guiding deviceincludes means for rotating at least one pair of said readilycompressible, resilient rollers, the rest of said rollers being freelyrotatable, said driven rollers being positioned ahead of saidfreewheeling rollers whereby said driven rollers drive said cant throughsaid freely rotatable rollers and into said second sawing apparatus. 20.The device of claim 19 in which said first centering and guiding devicein which all of said readily compressible, resilient rollers are freelyrotatably mounted, said first centering and guiding device including adrive chain passing generally between said rollers for driving a logtherebetween.